Temperature Dependence of the Heat Escape Time Deduced From the Nucleation of a Dissipative Zone in Superconducting YBa2Cu3O7 Filament

The application of an overcritical current pulse
$I > I_{c}(T)$
to narrow YBa
₂
Cu
₃
O
₇
strips generates a phase-slip center after a certain delay time
$t_{d}$
. By analyzing this function
$t_{d}(I/I_{c})$
through a time-dependent Ginzburg–Landau theory, one can extract the time of heat escape
$\tau_\mathrm{esc}$
from the film to the substrate. The parameter
$\tau_\mathrm{esc}$
was found to remain constant in the range from 5 to 40 K, but to increase notably above 40 K and up to
$T_{c}$
. We interpret this behavior as a manifestation of a Kapitza heat transfer by acoustic phonon radiation. The loss of transmissivity at higher temperatures is likely related to the rise of phonon–phonon decay processes.